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    Hopefully, the big wiring thread

    I haven't seen this covered before, so here we go. You've just dropped five large or more on the latest Ripsnotter 5000 motor, have a battery pack that you can weld with, and you're going to make a killah e-bike So you grab the crimp connectors, a roll of electrical tape, and start off. NOOOOOO!

    A lot of ebike kits come with wiring that is total crap. The better brands are actually coming with some nice connections and fairly reasonable wires for the service they will be put to, but this is only after suppliers tried some combinations that are obviously not going to work for very long. The best motor and battery combo is only as good as the wires that connect them together. And, unless you live in a place very different than where I live, the wiring system of an ebike has tough duty. Heat, cold, water, dust, vibration, and heavy loads factor in. The wires that are the pipes that bring the fuel from the battery to the motor. They need to be clean, robust, and hopefully no longer than absolutely necessary if you're going to have the best performance. After wiring motorcycles, boats, and even aircraft, I have some ideas on how to make a system that will take the punishment, and I'm sure that there are others that have some wisdom also.

    #2
    I just got a couple of kits in. One is from Lunacycles, and I was really pleased with the quality of the wiring harness. Except for two connections that will need to be soldered (or joined in ways I hope to cover later), the whole thing is plug and play, and some thought was given to make it weather resistant. Although it's touted as "waterproof," there are a few things that can be done to improve it that require very little cost and effort.

    Do you know about dielectric grease? You wouldn't stick a motor together without lubrication, and DE grease does the same for your wires. it provides a barrier to moisture, dirt, salt and the rest of the nasties that are going to make your wires unhappy. It's not cheap. They will stick you for six bucks or so at the hardware store for a tiny tube, but if you go to an electrical supplier, a big bottle costs between $15 and $20, and will last you most of your natural life, unless you are an electrician by trade.

    Comment


      #3
      Hope to see some good info here. I have plenty of crimp terminals, soldering equipment (I usually crimp and then solder the important connections), heat shrink, tape and DE grease at the ready in case anything needs to be "improved" as I'm installing my e-bike kit, hopefully by this weekend.

      Comment


        #4
        To put it in perspective, most manufactures are practicing what I call lawn mower engineering. Consumer lawn mowers are designed to run a couple of hundred hours before they fail. That is all most consumers need. On the other extreme are semi trucks. They are designed to run 10,000 hours between overhauls.

        Much of the current generation of electric bikes are designed closer to the lawn mower end of the spectrum. Many ebikes are only ridden a few hundred hours. The rest of the time they live in the garage. This is just the nature of economics. Consumers try to minimize price while manufactures and vendors compete to meet those price points. So corners get cut.

        So, looking forward to seeing how you apply your knowledge and experience to make electric bikes better and more reliable.

        Comment


          #5
          Dielectric grease is your friend. It's high-purity silicone grease, and is actually an insulator. Why would you want to put it on your wires? Well, because wires on e-bikes, motorcycles and boats, for example, live in a pretty harsh environment. There's water, salt, chemicals, grit, and plenty of other nasty substances that want to turn your nice, shiny wires into a black and crusty mess that doesn't work very well. The silicone grease keeps a lot of these things at bay. "Well," you say, "My bike has waterproof connectors." So does mine. and I can tell you that they are not completely waterproof. Also, when they get packed full of fine road grit, they become difficult to pop apart. The grease helps block the grit, water and other nasties from the metal pins, and lubricates the plastic bits as well. It seals out oxygen, which is a big ingredient in corrosion. Every time I make a connection, I'll squirt a small dab on the interface. When I am soldering a connection, I squirt a little bit under the shrink tube before I shrink it down. It really extends the life of things.
          Last edited by Canuman; 03-15-2017, 12:36 PM.

          Comment


          • Rider
            Rider commented
            Editing a comment
            Isn't dielectric grease designed for "single" connectors only and allows the transfer of electricity to pass through it? I'd hate to see someone think a gob of dielectric grease on a dual or triple connector will seal it up. Wouldn't that allow the transfer of electricity between the separate and distinct wires on a multiple wire connector? I'm I completely wrong on this or is it worth pointing out? Good thread by the way.

          • calfee20
            calfee20 commented
            Editing a comment
            Dielectric grease is non conductive.

            From an article I found "In regular low voltage multiple-pin circuit connectors, such as automotive applications, flooding with a proper insulating grease of low-viscosity dielectric grease is perfectly acceptable unless a manufacturer recommends against it. The grease should have good stability and not contain metals in any form, and be specifically designed for use as a dielectric grease. This generally is a silicone dielectric grease, although some Teflon based greases are acceptable."

            http://www.w8ji.com/dielectric_greas...ive_grease.htm

          • Rider
            Rider commented
            Editing a comment
            Good to know Calfee20! I've always avoided using it on multi-connectors, but I guess my fears were unjustified. Thanks.

          #6
          Electrical tape is so 80's. It also doesn't really work in the environment that many bikes will experience. It's made to live in a sedate environment, and doesn't do much to seal out the nasties. Luckily, there is silicone tape also. It's fairly expensive -- while a roll of electrical tape might cost a buck, the silicone stuff costs between four and ten bucks for about ten feet, depending where you buy it. It's stretchy and sticks to itself, and will eventually fuse to itself strongly enough that it cannot be pulled apart -- and creat an air and water-tight seal. It's great for shielding things that may need to be pulled apart on occasion. It leaves no residue, and will function in temps that are far beyond what you will encounter. It insulates to 8000 volts per layer. I really, really like this stuff. It makes a very professional-looking and durable seal.

          Comment


          • AZguy
            AZguy commented
            Editing a comment
            I really like this stuff but there are a few caveats.

            Wash your hands or wear gloves - getting contamination, especially oils hurts it's ability to self-adhere.

            Plan the wrapping so that the end you start with gets completely covered by a wrap and then put some heat shrink over the last wrap to prevent it from unwrapping. It takes time for it to fuse and the end likes to come loose and will continue to unwrap.

          #7
          Wire is wire, right? Nope. And unfortunately, much of the wiring on e-bikes tends to be designed by accountants, not by people that design electrical things. Good wire is expensive. Really good wire is really expensive. While there are plenty of metals that will conduct electricity, for cost, flexibility, and efficiency, it's hard to beat copper. One way that some manufacturers cheap out on wire is to replace some of the costly copper with other metals. The resulting mix looks like copper, but won't last nearly as long or function nearly as well. My brother (who makes his living designing and building custom amplifiers) claims that a lot of the electrical problems that plagued British motor vehicles were because the Brits were trying to stretch their precious copper supplies in this way. during WWII. There was a ton of the stuff around after the war, (a bomber has miles of wires in it) and it endured on the UK market well into the '70s. Having rebuilt a classic Land Rover in an attempt to remedy the "Prince of Darkness" electrics, I know the stuff goes all black and crumbly as it deteriorates.

          If you go to the local discount auto parts store, you're likely buying wire manufactured in Asia. You can get far superior stuff, if you're willing to pay the price. Aircraft-grade wire (try Aircraft Spruce and Specialty) is much better than automotive grade, although significantly more expensive. Really the nicest stuff is marine grade wire. It's meant to live in a corrosive salt-water environment, so they do things like tinning the individual strands. This seals out salt and moisture and oxygen that could cause corrosion. It also makes it a real treat to solder. The stuff solders as nicely as anything I've tried, and makes you look like a pro. The down side is that 14 gauge costs about thirty cents a foot, if you buy it retail. However, it's the real deal. It's also not something that I'd buy off Ebay, for example. It's pretty hard to tell the genuine article from counterfeit, and a buddy of mine dropped a pile on stuff that was claimed to be the real deal (the seller used spools from the real stuff) and had to re-do significant parts of his work after a couple of years of chasing unexplained shorts and failures. Defender Marine is a pretty good source for stuff like this, and if you only need a couple of feet of it for a job, they will often sell it by the foot at West Marine -- or you can visit your local marina, if there happens to be one near you.

          Comment


          • staplebattery
            staplebattery commented
            Editing a comment
            I've heard the marine grade shrink wrap has the grease in it already. And I usually use recycled wire and components when possible. I think the good copper wire rarely fails it's usually the connections right?

          #8
          I have a real problem with crimp connectors, to tell the truth. I have the pro-grade crimper ($60+ dollars) and buy high grade sleeves, usually 3M when I use them. A crimp may get you through in a pinch, but I really don't think they are a permanent solution. Unfortunately, when you're in a tight location, it's often difficult to solder properly. A friend who had been a crew chief maintaining helicopters turned me on to what I feel is a better solution. There are a variety of different sleeves made by a company called Posi-Lock. https://www.posi-products.com/ Again, these babies are kind of expensive, but they provide an excellent, reliable connection that's much stronger than a crimp. The connectors are reusable, and they don't promote corrosion on the wire. They look spiffy.

          Comment


          • calfee20
            calfee20 commented
            Editing a comment
            Do you have a photo of your pro grade crimper? Does it have compound leverage?

          • staplebattery
            staplebattery commented
            Editing a comment
            I'm thinking I might leave slack in my wires on my next build so if there's a failure somewhere on the road I can always strip, twist and tape my way home...

          • staplebattery
            staplebattery commented
            Editing a comment
            i just realized that if that comment was cited without the forum it could easily be taken out of context...

          #9
          Yes, it's the ratcheting model from Klein. I don't have a pic right on hand, but one can be found here: https://www.kleintools.com/catalog/r...heting-crimper

          It's overkill for home use. You can get one that will get you by for a third of the price at Home Depot or Harbor Freight. They do a far superior job to the cheap pliers type crimper you'll find for a few bucks.
          Last edited by Canuman; 03-17-2017, 07:29 AM.

          Comment


            #10
            Have one like that at the office that I use for terminating CAT5/6 cables (made specifically for network cable). Pretty good stuff.

            Comment


            • staplebattery
              staplebattery commented
              Editing a comment
              I was thinking of using cat-5 for my hall sensor connection from motor to controller. Not the connectors, just the wire

            #11
            For heavy guage wire i use http://www.harborfreight.com/hydraul...ool-66150.html . It is a bit clumsy so I wouldn't want to depend on it to make a living. I also ended up making all new dies for it. The dies that came with it were pretty dodgy.

            A couple of weeks ago, I picked up https://www.amazon.com/gp/product/B0...1?ie=UTF8&th=1 in the 14 -16 guage size to pratice crimping. Overall I am happy with it. The crimping surfaces are pretty soft so I don't expect a real long life. Probably good enough for home use.

            If you do jst-sm connectors https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 is a life saver.

            I haven't decided what to do in the 10-12 gauge range.

            I am also on the look out for a good source of sleeves for hobbyist and home builders :)

            Comment


              #12
              What do you guys think of heatshrink solder sleeves? Seb did a video trying these out for our BMS documentation.
              Seems to work best on smaller wire and relatively foolproof, cheap and requires few extra tools. You reckon the heatshrink will hold up for many years, or would some of that nice silicone tape be good to wrap on top? Found a video on those posi-lock connectors, doesn't look like they list a max current rating? Looks interesting though! (Edit: was told by manufacturer the connector can handle more current than the wire. Getting a few to test that statement)

              Comment


              • calfee20
                calfee20 commented
                Editing a comment
                I didn't even know the solder crimpless butt connectors even existed. I think there will be a fine line between burning through the shrink wrap and getting the soldered connection right.

              • Nick R.
                Nick R. commented
                Editing a comment
                WOW what a great post, as a newbie I now feel confident that I can make at least a reasonable joint. My next question is going with large wire (12g) for all connections ok or am I heading for trouble. Nick R.

              • AZguy
                AZguy commented
                Editing a comment
                Nothing beats a *properly done* crimp but plenty of folks find the properly done part a bit tricky so these might have a space in time for those...

              #13
              If they work they look like they could be a solution to a hard problem for a lot of new builders.

              My concern would be that the torch heats the solder rather than the wire. The problem with most inexperienced people is that they heat a blob of solder on their iron and then dab it on the connection. This results in a cold joint. It is neither mechanically nor electrically solid or reliable.

              Even something as simple as instructing the builder to hold the connection in hot part of the flame for x number of second after the solder melts might solve that concern.

              Before recommending these, I would suggest that someone make up bunch and then use a Dremel tool with a circular cutter to cut them open to make sure then the solder has wetted completely to all (or at least) most of the individual wire strands.

              Comment


              • axmking
                axmking commented
                Editing a comment
                I don't know about all solder sleeves but the ones I've used have an indicator band on them that only changes once the solder has fully leeched into the strands

              #14
              When I put my bike together the BBHSD from Luna had nice beefy 10 ga wires but the slimline battery leads were a skinny 14 ga. This worried me even though I kept telling myself the battery people must know what they are doing. I found this calculator online that eased my fears. http://www.electriciancalculators.co...cond_size.html

              Evidentially DC is considered the same as single phase AC. So enter 48 volts dc or if you want to increase your margin of safety enter 120 volts 1 phase. I used a max of 30 amps and a 3% voltage drop. The only wires I was worried about were the battery leads that were less that 2 feet in total length so I entered that and hit calculate. As you can see for short lengths of wire surprisingly small gauge wires can be used.

              It took me a while to find this calculator again so I am putting it in my favorites. Another thing you should remember is that electricity flows down the surface of the wire and it only flows through the wire when the amps get toward capacity. This is why finely stranded wire will carry more current than stranded wire. My battery wires were very finely stranded. While playing with the calculator you can see that even 120 volts, 30 amps, and 10 feet of wire was still OK with a 14 ga wire.

              Comment


              • Rider
                Rider commented
                Editing a comment
                That 10ga to 14ga kind of struck me as strange too, but I know the Luna Panasonic-Sanyo GA 21Ah battery I'm using is top notch stuff with XT90 connectors supplied. I "assume" Bafang knows what gauge wire is needed to supple the amps, volts and watts the BBS02 750W/48V motor is designed for, so I simply used quality step-down butt wire connectors that I crimped, soldered and used double heat-shrink (one piece on each wire and a larger piece over both connectors). Working great so far and looked neat and clean too.

              • AZguy
                AZguy commented
                Editing a comment
                DC flows through the entire conductor not just the outside. The skin effect may be what you are referring to is when there is AC current that creates an AC magnetic field that "pushes" the flow towards the outside of the conductor perpendicular to the direction of travel effectively increasing the resistance in the center.

              #15
              For really good connections get submersble pump connectors, wire. home depot etc. Heavy duty crimps and silicone filled heat shrink. Very water proof. Made to last years with constant use under water.

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